Get operation by ID or ref

[glen-84]

Is your feature request related to a problem? Please describe.

I have an OpenApiLink object, which has either an OperationId or an OperationRef, but I can't find a way to access the Operation object that these refer to.

Describe the solution you'd like

Either an Operation property on the OpenApiLink object that holds the "resolved" operation, or methods like openApiDocument.GetOperationById(string operationId) and openApiDocument.GetOperationByRef(string operationRef).

Describe alternatives you've considered

For operation IDs, constructing a dictionary of operations, keyed by operation ID, and using that. I don't know about operation refs though.

Additional context

n/a